Battery Rack Having Multiple Fire Safety Features, and Applications Thereof

ABSTRACT

Provided is a battery module and battery rack having enhanced fire safety features. The battery module includes a swelling/pressure sensor that detects swelling of a battery cell. An output signal of the sensor is used to halt operation of a battery rack/battery system containing the battery module and prevent charging and discharging of the battery module. In an embodiment, the battery module uses an AC-to-AC power supply to provide AC frequency power for balancing battery cells of the battery module. In an embodiment, the battery rack includes an internal water fire suppression system that provides battery cooling in the event of a battery cell fire to prevent the spread and/or reigniting of the fire.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is concurrently filed with U.S. application Ser. No.17/691,948 (Atty. Dkt. No. 4860.0010007) and is a continuationapplication of PCT International Application No. PCT/US2022/013290,filed Jan. 21, 2022; which is a continuation application of U.S.application Ser. No. 17/531,378, filed Nov. 19, 2021; which claims thebenefit of U.S. Provisional Patent Application 63/211,732, filed Jun.17, 2021; U.S. Provisional Patent Application 63/170,600, filed Apr. 5,2021; U.S. Provisional Patent Application 63/164,502, filed Mar. 22,2021; U.S. Provisional Patent Application 63/125,958, filed Dec. 15,2020; and U.S. Provisional Patent Application 63/123,458, filed Dec. 9,2020. Each of the above applications is herein incorporated by referenceas if fully reproduced below.

TECHNICAL FIELD

The present disclosure relates to battery energy storage systems.

BACKGROUND

Battery energy storage systems use a lot of batteries, which present afire hazard if not properly managed. Conventional battery managementsystems typically just monitor battery cell voltages and temperatures.They do not monitor or indicate the internal state of the battery cells.Battery cell voltages as well as cell temperatures are not in themselvesgood indicators of changing conditions/pressure inside the cells thatcan lead to a battery fire.

SUMMARY

The embodiments featured herein help solve or mitigate theabove-mentioned issues as well as additional shortcomings relating tobattery storage systems.

Under certain circumstances, an embodiment of the invention includes abattery module having a sensor that detects swelling of a battery cell.An output signal of the sensor is used to halt operation of a batteryrack/system containing the battery module and thereby halt charging anddischarging of the battery cell until the battery module containing thebattery cell can be replaced and the battery rack/system inspected toverify it is safe to operate.

In an embodiment, high frequency AC power is used as a power source forbalancing the battery module cells. Using high frequency AC powerpermits the use of isolation transformers as a part of the cellbalancing circuit.

In an embodiment, battery modules according to the invention include atop cover that collects water and directs this water to plates of thebattery module to cool the battery.

In an embodiment, battery racks according to the present inventioninclude a water fire suppression system having a cascading water flowamong the battery modules, which provides cooling in the event of abattery cell fire and thereby controls and prevents the spread of abattery cell fire to neighboring cells and racks.

In an embodiment, battery racks according to the present inventioninclude an exhaust duct to remove gases and/or heat and direct thesegases and/or heat outside of the room, container, building, etc. thathouses the battery rack.

Further features and advantages of the disclosure, as well as thestructure and operation of various embodiments, are described in detailbelow with reference to the accompanying drawings. It is noted that thedisclosure is not limited to the specific embodiments described herein.Such embodiments are presented herein for illustrative purposes only.Additional embodiments will be apparent to persons skilled in therelevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Together with the following detailed descriptions, the accompanyingdrawings illustrate a number of exemplary embodiments in addition todescribing and demonstrating various aspects and/or principles set forthin the present disclosure. The accompanying drawings and the briefdescriptions are provided to enable one of ordinary skill in the art topractice the various aspects and/or principles set forth in the presentdisclosure.

FIG. 1 illustrates an example battery module according to an embodimentof the present invention.

FIG. 2A illustrates the front cover of the battery module of FIG. 1.

FIG. 2B illustrates the battery module of FIG. 1 with the front coverremoved.

FIG. 3A illustrates an exploded view of the battery module in FIG. 1.

FIG. 3B illustrates the battery module of FIG. 1 with handle strapsinstalled.

FIG. 4A illustrates the battery module of FIG. 1 with the top coverremoved.

FIG. 4B illustrates an example of a swelling/pressure sensor for thebattery module of FIG. 1.

FIG. 5 illustrates a rear view of the battery module of FIG. 1 with thetop cover removed.

FIG. 6 illustrates an example swelling/pressure sensor that may be usedaccording to embodiments of the present invention.

FIGS. 7A-B illustrate an example swelling/pressure sensor that may beused according to embodiments of the present invention.

FIGS. 8A-B illustrate an example swelling/pressure sensor that may beused according to embodiments of the present invention.

FIGS. 9A-B illustrate an example swelling/pressure sensor that may beused according to embodiments of the present invention.

FIG. 10 illustrates an example swelling/pressure sensor that may be usedaccording to embodiments of the present invention.

FIG. 11A illustrates an example swelling/pressure sensor that may beused according to embodiments of the present invention.

FIG. 11B illustrates an example swelling/pressure sensor that may beused according to embodiments of the present invention.

FIGS. 11C-H illustrate an example top tray with integratedswelling/pressure sensors according to embodiments of the presentinvention.

FIG. 12A illustrates a circuit that may be used with swelling/pressuresensors according to embodiments of the present invention.

FIG. 12B illustrates a circuit that may be used with swelling/pressuresensors according to embodiments of the present invention.

FIG. 13 illustrates an example battery module according to an embodimentof the present invention.

FIG. 14 illustrates an exploded view of the battery module in FIG. 13.

FIG. 15 illustrates an example swelling/pressure sensor for the batterymodule of FIG. 13.

FIG. 16 illustrates an example swelling/pressure sensor for the batterymodule of FIG. 13.

FIG. 17 illustrates an example swelling/pressure sensor for the batterymodule of FIG. 13.

FIG. 18 illustrates an example battery module according to an embodimentof the present invention.

FIG. 19 illustrates an example battery module according to an embodimentof the present invention.

FIGS. 20A-B illustrate an example battery assembly according to anembodiment of the present invention.

FIG. 21 illustrates an exploded view of the battery module in FIG. 19.

FIG. 22 illustrates an example battery module with the front coverremoved according to an embodiment of the present invention.

FIG. 23 illustrates an example battery module according to an embodimentof the present invention.

FIGS. 24A-B illustrate load cells/gauges that may be used in embodimentsof the present invention.

FIG. 25 illustrates a load cells/gauge that may be used in embodimentsof the present invention.

FIG. 26 illustrates an example battery module with the front cover andtop cover removed according to an embodiment of the present invention.

FIG. 27 illustrates an example swelling/pressure sensor that may be usedaccording to embodiments of the present invention.

FIG. 28 is a diagram showing how movement of the sensor of FIG. 27applies stresses to strain gauges.

FIG. 29 is a diagram showing how to connect strain gauges of a sensor ina Wheatstone bridge configuration.

FIG. 30 is a diagram showing a circuit for converting the output ofstrain gauges to a serial digital signal.

FIG. 31 illustrates a battery module having two pressure plates andeight battery cells.

FIG. 32 illustrates a swelling/pressure sensor attached to pressureplates of a battery module.

FIG. 33 illustrates two applied pressure assemblies attached to twopressure plates of a battery module.

FIG. 34 illustrates an applied pressure assembly with integrated sensorthat has a leaf spring.

FIG. 35 illustrates an applied pressure assembly with integrated sensorthat has a die spring.

FIG. 36 illustrates features of an example center plate and bottom platefor a battery module according to an embodiment of the presentinvention.

FIG. 37 illustrates a battery module side plate according to anembodiment of the present invention.

FIG. 38 illustrates an example battery module controller according to anembodiment of the present invention.

FIG. 39 illustrates an example battery module controller according to anembodiment of the present invention.

FIG. 40 illustrates example battery module controllers according toembodiments of the present invention.

FIG. 41 illustrates example battery module controllers according toembodiments of the present invention.

FIG. 42 illustrates an example battery module power supply according toan embodiment of the present invention.

FIG. 43 illustrates an example cell charging/balancing circuit that canbe used in embodiments of the present invention.

FIG. 44 illustrates an example cell charging/balancing circuit that canbe used in an embodiment of the present invention.

FIG. 45 illustrates an example cell charging/balancing circuit that canbe used in an embodiment of the present invention.

FIG. 46 illustrates an example battery module controller according to anembodiment of the present invention.

FIG. 47 illustrates an example battery module controller according to anembodiment of the present invention.

FIG. 48 (separated into the partial views shown in FIGS. 48A-48Q)illustrates an example battery module controller according to anembodiment of the present invention.

FIG. 49 illustrates an example power supply of a battery modulecontroller according to an embodiment of the present invention.

FIG. 50 (separated into the partial views shown in FIGS. 50A-50D)illustrates an example power supply of a battery module controlleraccording to an embodiment of the present invention.

FIG. 51 illustrates features of a battery module according to anembodiment of the present invention.

FIG. 52 illustrates an example battery rack controller according to anembodiment of the present invention.

FIG. 53 illustrates an example battery rack controller according to anembodiment of the present invention.

FIGS. 54A-B illustrate an example battery rack according to anembodiment of the present invention.

FIG. 55 illustrates an example battery rack according to an embodimentof the present invention.

FIGS. 56A-B illustrate an example battery rack according to anembodiment of the present invention.

FIGS. 57A-C illustrate example battery racks according to embodiments ofthe present invention.

FIG. 58 illustrates a fire suppression system for a battery rackaccording to an embodiment of the present invention.

FIGS. 59A-B illustrate a fire suppression system for a battery rackaccording to an embodiment of the present invention.

FIG. 60 illustrates an example battery module according to an embodimentof the present invention.

FIG. 61 illustrates an example battery rack according to an embodimentof the present invention.

FIGS. 62A-B illustrate an example battery rack according to anembodiment of the present invention.

FIGS. 63A-B illustrate an example battery rack according to anembodiment of the present invention.

FIG. 64 illustrates an example battery rack according to an embodimentof the present invention.

FIG. 65 illustrate an example container system for housing battery racksaccording to the present invention that form a battery energy storagesystem.

FIG. 66 illustrates multiple containers housing battery racks accordingto the present invention that form a battery energy storage system.

FIG. 67 illustrates a building that houses battery racks according tothe present invention that form a battery energy storage system.

DETAILED DESCRIPTION

Embodiments will be described below in more detail with reference to theaccompanying drawings. The following detailed descriptions are providedto assist the reader in gaining a comprehensive understanding of themethods, apparatuses, and/or systems described herein as well asmodifications thereof. Accordingly, various modifications andequivalents of the methods, apparatuses, and/or systems described hereinwill be apparent to those of ordinary skill in the art. Descriptions ofwell-known functions and constructions may be omitted for increasedclarity and conciseness.

FIG. 1 illustrates an example battery module 100 according to anembodiment of the present invention. As shown more clearly in FIG. 3A,battery module 100 includes several features that enhance fire safetyand can prevent a battery fire.

Over time, a battery cell within a battery module may become damaged andbegin to swell. This swelling is a very good indication of a change inthe internal pressure of the cell and is a very good indicator that thecell might catch on fire if not replaced. The swelling can be caused,for example, by the formation of flammable and explosive gases insidethe cell due to changes in the electrolyte and other active materialsinside the battery cell. Cell swelling occurs before a cell vents and/orcatches on fire.

As described herein, a new swelling/pressure sensor is designed andinstalled on battery modules according to embodiments of the presentinvention that can detect and quantify the amount of swelling/pressurein the battery cells. When swelling/pressure beyond normal cyclingchanges is detected using firmware/software and data from the sensors,an alarm/warning is generated by the firmware/software so that actioncan be taken whereby the battery cells having the abnormalswelling/pressure can be replaced before the cells vent or can progressto a point where a fire is likely to occur. The alarm/warning can alsobe used to automatically disconnect, for example, the battery rackcontaining the battery cells having the abnormal swelling/pressure sothat the battery cells are not further charged or discharged and thusfurther damaged, which could lead to the venting of the battery cellsand/or a battery cell fire.

In one embodiment, as described in more detail below, oneswelling/pressure sensor can be used to monitor several cells at once byattaching the sensor to plates of a battery assembly or battery module.In another embodiment, the swelling/pressure sensor(s) is/are attachedto the battery cell(s) directly. As described herein, the detection ofabnormal swelling/pressure in a battery cell can be used to shut downthe battery system and make it safe until a cell having an issue isreplaced and the system is inspected to make sure it is safe to operateagain.

FIG. 2A illustrates a front cover 200 of battery module 100. Front cover200 includes a handhold 201 for lifting and for carrying battery module100.

FIG. 2B illustrates battery module 100 with front cover 200 removed. Asshown in FIG. 2B, battery module 100 includes battery cells 202 a and202 b. These battery cells have a predetermined amount of pressureapplied to them using side plates 203, side bars 204 a and 204 b, and aspring 206. Applying a predetermined amount of pressure to battery cells202 can increase the cycle life of battery cells 202. By using spring206 to apply this pressure, the side plates 203 are still free to movedue to swelling/expansion of battery cells 202. As described in moredetail below, the movement of side plates 203 can be monitored andmeasured using sensors according to embodiments of the presentinvention.

FIG. 3A illustrates an exploded view of battery module 100. As shown inFIG. 3A, battery module 100 includes front cover 200, a back cover 300,battery cells 202 (e.g., 202 a, 202 b), side plates 203 (e.g., 203 a,203 b, 203 c), side bars 204 (e.g., 204 a, 204 b), a bottom plate 302,center plates 304, top tray 306, and a cover 308. Also included inbattery module 100 are battery module controller circuit boards 310 aand 310 b, busbars 312, sensors 314, and connectors 316.

In an embodiment, battery module 100 includes eight battery cells 202.However, fewer or more battery cells may be included in battery module100, such as two, four, six, ten, twelve, fourteen, sixteen, etc.Battery cells 202 are used for storing electrical energy. The eightbattery cells 202 are connected in series using busbars 312. Apredetermined amount of pressure is applied to battery cells 202 usingside plates 203, center plates 304, and side bars 204. Side plates 203and center plates 304 also provide cooling for battery cells 202. Toptray 306 fits on top of battery cells 202 and provides several functionsincluding providing a protective space for sensors 314 and batterymodule controller circuit boards 310 a and 310 b. Other functions of toptray 306 are described below. Cover 308 fits on top of top tray 306.Front cover 200 and back cover 300 are used, for example, to lift andcarry battery module 100. Front cover 200 includes connectors 316 thatallow for several battery modules 100 to be easily wired together toform larger battery systems. Battery module controller circuit boards,described in more detail below, provide battery management functions forbattery module 100 such as, for example, monitoring the voltage,temperature, and pressure of battery cells 202.

FIG. 3B illustrates battery module 100 with handle straps 318 a and 318b installed. As shown in FIG. 3B, handle straps 318 a and 318 b connectthe tops of front cover 200 and back cover 300 together for addedsupport when battery module 100 is lifted and carried.

FIG. 4A illustrates battery module 100 with top cover 308 and batterymodule controller circuit boards 310 a and 310 b removed. Thus, top tray306, busbars 312, and sensors 314 a-d are more clearly visible in FIG.4A. As can be seen in FIG. 4A, top tray 306 includes holes 400 a, 400 b,and 400 c. Holes 400 a and 400 c are on the sides of top tray 306. Holes400 b are in the center of top tray 306. Holes 400 allow air to flowover the side plates and through the center plates of battery module 100for cooling of the battery cells. As described in more detail below, theholes 400 also allow for water collected in top tray 306 from a waterfire suppression system to be channeled to flow over the side plates andthrough the center plates of battery module 100. The water flow can beinfluenced by the slope of the bottom of top tray 306.

FIG. 4B illustrates one example of a swelling/pressure sensor 314 forthe battery module 100. Other swelling/pressor sensors are describedbelow and can be used with battery modules according to embodiments ofthe present invention. FIG. 4B also shows in more detail the holes 400of top tray 306.

FIG. 5 illustrates a rear view of battery module 100 with cover 308removed. Many of the features of battery module 100 described herein canbe seen in FIG. 5.

FIG. 6 illustrates the working principles of an exampleswelling/pressure sensor 314 that may be used according to embodimentsof the present invention. As shown in FIG. 6, in an embodiment a sensor314 according to the present invention has a ring 600, which may bemetal or plastic or any other suitable material. Ring 600 includes twoattachment points, 602 a and 602 b, at which a force can be applied.When a force is applied at attachment points 602, ring 600 experiencestension and compression at locations 604 a-d as shown in FIG. 6. Inembodiments, one or more strain gauges are attached to ring 600 at oneor more of these locations and used to measure the tension and/orcompression at these locations. How this is done is explained in moredetail below.

FIGS. 7A-B further illustrate an example swelling/pressure sensor 314that may be used according to embodiments of the present invention. Asshown in FIG. 7A, sensor 314 includes a metal ring 700 and two plasticattachments 702 a and 702 b. The metal ring 700 is securely held onattachments 702 a-b by plastic caps 704 a and 704 b. In an embodiment,plastic caps 704 a and 704 b are coupled to attachments 702 a and 702 bto securely hold metal ring 700 in place. This coupling may be achievedusing an adhesive or glue. FIG. 7B shows an assembled sensor 314. One ormore strain gauges (not shown) are attached to metal ring 700 asdescribed herein.

FIGS. 8A-B illustrate an example swelling/pressure sensor 800 that maybe used according to embodiments of the present invention. As shown inFIG. 8A, sensor 800 includes a metal ring 802 and plastic attachments804 a and 804 b. In an embodiment, after metal ring 802 is inserted intoslots in plastic attachments 804 a-b, a small amount of glue or adhesivemay be applied to firmly secure metal ring 802 to plastic attachments804 a-b. FIG. 8B shows an assembled sensor 800. One or more straingauges (not shown) are attached to metal ring 802 as described herein.

FIGS. 9A-B illustrate an example swelling/pressure sensor 900 that maybe used according to embodiments of the present invention. As shown inFIG. 9A, sensor 900 includes two half metal rings 902 a and 902 b andtwo plastic attachments 904 a and 904 b. In an embodiment, after metalhalf rings 902 are inserted into slots in plastic attachments 904 a and904 b, a small amount of adhesive or glue may be applied to firmlysecure metal half rings 902 a-b to plastic attachments 904 a-b. FIG. 9Bshows an assembled sensor 900. One or more strain gauges (not shown) areattached to metal half rings 902 as described herein.

FIG. 10 illustrates an example swelling/pressure sensor 1000 that may beused according to embodiments of the present invention. Sensor 1000includes two metal half rings 1001 a and 1001 b, and a plasticattachment 1002 with a flexible center piece 1004 (which may be plasticor any other suitable material). The flexible center piece 1004 can helpwith the assembly of sensor 1000. One or more strain gauges (not shown)are attached to metal half rings 1002 as described herein.

FIG. 11A illustrates an example swelling/pressure sensor 1100 that maybe used according to embodiments of the present invention. As shown inFIG. 11A, sensor 1100 includes two oval-shaped half metal rings 1102 aand 1102 b and two plastic attachments 1104 a and 1104 b. In anembodiment, after oval-shaped metal half rings 1102 are inserted intoslots in plastic attachments 1104 a and 1104 b, a small amount ofadhesive or glue may be applied to firmly secure metal half rings 1102a-b to plastic attachments 1104 a-b. as shown in FIG. 11A, one or morestrain gauges 1106 are attached to oval-shaped metal half rings 1102 asdescribed herein.

FIG. 11B illustrates an example swelling/pressure sensor 1110 that maybe used according to embodiments of the present invention. As shown inFIG. 11B, sensor 1110 includes a single part 1111 and one or more straingauges 1112 attached to plastic part 1111. The single part 1111 may bemade entirely of plastic or any suitable material. Sensor 1110 can beless expensive to make and assemble than other sensors according to thepresent invention described herein.

FIGS. 11C-H illustrate an example top tray 1130 with integratedswelling/pressure sensors 1132 a-d according to an embodiment of thepresent invention. FIG. 11C is a top view of example top tray 1130, inwhich the four integrated swelling/pressures sensors 1132 a-d can beseen. These sensors are similar to sensor 1110 in FIG. 11B. FIG. 11D isa bottom view of top tray 1130. In FIG. 11D, one can see the holes 400a-c that are used to direct water to the side plates and center plate ofa battery module according to the present invention in order to cool thebattery cells in the event of a battery cell fire. FIG. 11E is asectional view of top tray 1130 that shows sensors 1132 a and 1132 b.FIG. 11F shows top tray 1130 installed on a battery module 100 accordingto the present invention. In FIG. 11F, one can see the installed batterymodule controller circuit boards 310 a-b installed on the battery moduleand see how top tray 1130 protects the circuit boards. FIG. 11G furtherillustrates top tray 1130 and one of its integrated sensors 1132 c. FIG.11H is a sectional view that further illustrates top tray 1130 with itsintegrated sensor 1132 c installed on a battery module 100.

In other embodiments of the present invention, other sensors accordingto the present invention are integrated into a top tray of a batterymodule. For example, in embodiments, sensors similar to those shown inFIGS. 7A-B, FIGS. 8A-B, FIGS. 9A-B, FIG. 10, and FIG. 11A can beintegrated into a top tray as shown in FIGS. 11C-H. Integrating sensorsaccording to the present invention into the top tray can, for example,reduce manufacturing costs, tooling costs, labor costs, etc.Additionally, while the ring(s) of the sensors shown in FIGS. 7A-B,FIGS. 8A-B, FIGS. 9A-B, FIG. 10, and FIG. 11A were described as beingmetal, any suitable material may be used. Similarly, while theattachment(s) and cap(s) of the sensors shown in FIGS. 7A-B, FIGS. 8A-B,FIGS. 9A-B, FIG. 10, and FIG. 11A were described as being plastic, anysuitable material may be used.

FIG. 12A illustrates a circuit 1200 that may be used withswelling/pressure sensors according to embodiments of the presentinvention. Circuit 1200 is a Wheatstone bridge circuit. As shown in FIG.12A, circuit 1200 includes a voltage source 1202, three fixed resistancevalues 1204 a-c, and a variable resistance value 1206. In embodiments ofthe present invention, variable resistance 1206 is a swelling/pressuresensor as described herein. In operation, a voltage is applied to theWheatstone bridge circuit, and any change in the resistance of a straingauge that forms a part of a swelling/pressure sensor due to theswelling of a battery cell that forms a part of a battery module isdetected as a change in the output voltage shown in FIG. 12A. One ormore strain gauges may be coupled to (e.g., wired to) one or more of thebattery module controller circuit boards.

FIG. 12B illustrates a circuit 1210 that may be used withswelling/pressure sensors according to embodiments of the presentinvention. Circuit 1210 is a Wheatstone bridge circuit with fourvariable resistances 1212 a-d. In embodiments, each of the four variableresistances 1212 is a swelling/pressure sensor as described herein. Aselection circuit of multiplexer circuit 1214 is used to select whichvariable resistor or sensor is used when the output voltage is measuredor determined using battery module controller circuit boards 310 a-b. Inone embodiment, voltage source 1202 is a 12V voltage source, and eachvariable resistance 1212 is a 350 Ohm strain gauge that forms a part ofa swelling/pressure sensor according to embodiments of the presentinvention. In another embodiment, each variable resistance 1212 iscomprises two 350 Ohm strain gauges, connected in series, which form apart of a swelling/pressure sensor according to embodiments of thepresent invention. These two strain gauges are attached, for example, atlocations 604 a and 604 c as shown in FIG. 6.

FIG. 13 illustrates an example battery module 100 according to anembodiment of the present invention with top 308 removed. As shown inFIG. 13, in this embodiment, battery module 100 has fourswelling/pressure sensors 1500. Sensor 1500 is described in more detailbelow.

FIG. 14 illustrates an exploded view of the battery module 100 shown inFIG. 13. As shown in FIG. 14, battery module 100 includes front cover200, a back cover 300, battery cells 202 (e.g., 202 a, 202 b), sideplates 203 (e.g., 203 a, 203 b, 203 c), side bars 204 (e.g., 204 a, 204b), springs 206 (one at each end of battery module 100), a bottom plate302, center plates 304, top tray 306, and a cover 308 (shown in FIG.13). Also included in battery module 100 are battery module controllercircuit boards 310 a and 310 b, busbars 312, and four sensors 1500.

In an embodiment, battery module 100 includes eight battery cells 202.Battery cells 202 are used for storing electrical energy. The eightbattery cells 202 are connected in series using busbars 312. Apredetermined amount of pressure is applied to battery cells 202 usingside plates 203, center plates 304, springs 206, and side bars 204. Sideplates 203 and center plates 304 also provide cooling for battery cells202. Top tray 306 fits on top of battery cells 202 and provides severalfunctions including providing a protective space for sensors 1500 andbattery module controller circuit boards 310 a and 310 b. Otherfunctions of top tray 306 are described below. A cover 308 (shown inFIG. 13) fits on top of top tray 306. Front cover 200 and back cover 300are used, for example, to lift and carry battery module 100. Front cover200 includes connectors 316 that allow for several battery modules 100to be easily wired together to form larger battery systems. Batterymodule controller circuit boards, described in more detail below,provide battery management functions for battery module 100 such as, forexample, monitoring the voltage, temperature, and pressure of batterycells 202.

FIG. 15 illustrates an example all plastic swelling/pressure sensor 1500for the battery modules according to embodiments of the presentinvention. As shown in FIG. 15, sensor 1500 includes a plastic part 1502and a strain gauge 1504 attached to part 1502. When a force is appliedto the ends of part 1502, the strain gauge 1504 stretches or compresses,thereby changing the resistance of the strain gauge. This change inresistance can be detected, for example, using circuit 1210 describedabove. In other embodiments, swelling/pressure sensor 1500 can be madefrom any other suitable material.

FIG. 16 further illustrates how an example swelling/pressure sensor,like sensor 1500, can be made and used. As shown in FIG. 16, inembodiments, one or more strain gauges 1602 are attached to the top of aplastic part 1604. The strain gauges can be attached using an adhesive.A thin section can be formed in part 1604 directly under strain gauge(s)1602 to facilitate, for example, expansion of this section when force isapplied to the ends of part 1604. In embodiments, the ends of part 1604are attached to the side plates or pressure plates of a battery module,such as the battery modules described herein.

FIG. 17 illustrates how an area of high local strain and stress isformed in part 1604 when a force is applied to the ends of part 1604.

FIG. 18 illustrates an example battery module 1800 according to anembodiment of the present invention. As shown in FIG. 18, a batterymodule 1800 has four battery cell assemblies 1802. Each battery cellassembly 1802 has two battery cells 202 a and 202 b, a middle plate 304,and two side plates 203 a and 203 b, which may act as heat sinks. Themiddle plate 304 is coupled to a bottom plate 302 of battery module1800. In an embodiment, the battery cells 202 are attached to the middleplate 304 and side plates 203, for example, by an adhesive ordouble-sided tape. Various commercially available adhesives and tapescan be used depending on the desired setting time, curing time,strength, and thermal conductivity.

In one embodiment, as shown in FIG. 18, each battery cell assembly 1800has its own swelling/pressure sensor such as, for example, sensor 1500.Sensor 1500 is attached to the two side plates 203. When one or both ofthe battery cells 202 swell, the side plates 203 move, and this movementis detected/measured by the sensor 1500. In an embodiment, this sensormay be made from a plastic strip and have strain gauge(s) attached tothe plastic strip as described above. The thickness of the plastic stripmay be varied to allow more stretching of the plastic strip in the areawhere the stain gauge(s) are attached. In other embodiments, sensorsother than 1500 are used as will be understood by persons skilled in therelevant art(s).

FIG. 19 further illustrates an example battery module 1800 according toan embodiment of the present invention. As shown in FIG. 19, batterymodule 1800 includes three side bars 204 a-c, which are used to applypressure to the battery cells. The three side bars 204 are connectedtogether using a bar 1900 and bolts. A spring 1902 controls the amountof pressure applied by the side bars 204 to the battery cells.

FIGS. 20A-B further illustrate an example battery assembly 1802according to an embodiment of the present invention. As shown in FIG.20B, in embodiments, bottom plate 302 has holes 2000 located wherecenter plate 304 attaches to bottom plate 302. Holes 400 permit air andwater to flow through center plate 304 without being blocked by bottomplate 302.

FIG. 21 illustrates an exploded view of battery module 1800. In FIG. 21,the various parts that form battery module 1800 can be seen more clearlythan in some of the other figures. These parts include, for example,battery cells 202, side plates 203, side bars 204, battery modulecontroller circuit boards 310 a and 310 b, and busbars 312.

FIG. 22 illustrates another embodiment of example battery module 1800according to the present invention with the front cover removed. In thisembodiment, side bars 204 a-c are connected together using a bar 2200,two spring 2202 a-b, and bolts. As shown in FIG. 22, in this embodiment,battery module 1800 includes a back cover 300, a top tray 306, and acover 308.

FIG. 23 illustrates an example battery module 2300 according to anembodiment of the present invention. As shown in FIG. 23, battery module2300 includes battery cells 202, side plates 203, and center plates 304.Pressure is applied to the side plates 203/battery cells 202 using sidebars 204 and two pressure assemblies 2310 a-b. One pressure assembly2310 is located at the two ends of battery module 2300 as indicated inFIG. 23.

As shown in FIG. 23, each pressure assembly 2310 includes a load cell2312, a connecting bar 2314, springs 2316, and bolts 2318. The pressureapplied to the side plates 203 and battery cells 202 is controlled bythe springs 2316 and can be adjusted using bolts 2318. In operation,when one or more of the battery cells 202 swell, they cause a movementof side plates 203 which applies a force to the load cells 2312 that areattached to the side plates. This movement is then detected andquantified by battery module controller circuit boards 310 a-b (see, forexample, FIG. 26).

FIGS. 24A-B further illustrate load cells 2312 that may be used inembodiments of the present invention. As shown in FIG. 24A, load cells2312 include one or more strain gauges 2400 located within the centerhole of load cell 2312. After the one or more strain gauges areinstalled, the center hole is typically filled with an epoxy to protectthe strain gauges and associated wires.

FIG. 25 illustrates the operation of a load cell 2312 that may be usedin embodiments of the present invention. As shown in FIG. 25, the straingauges are located in one or more locations within the center hole ofload cell 2312 to measure the compression and/or tension caused byapplying a force to the ends of load cell 2312. In the embodiment shownin FIG. 25, four strain gauges 2400 a-d are installed. This embodimentcan be used, for example with the circuits shown below in FIG. 29 andFIG. 30.

FIG. 26 illustrates an example battery module 2600 with the front coverand top cover removed according to an embodiment of the presentinvention. As shown in FIG. 26, battery module 2600 includes a pressureassembly 2602, which includes a load cell 2604. The load cell 2604 iswired to one or both of the battery module controller circuit boards 310a-b. The output of the load cell 2604 is monitored and quantified usingbattery module controller circuit boards 310 a-b.

FIGS. 27 and 28 illustrate an example swelling/pressure sensor 2700 thatmay be used according to embodiments of the present invention. As shownin FIG. 27, sensor 2700 includes two supports 2702 a-b, two flexors 2704a-b (which may be metal or plastic of any other suitable material), andfour strain gauges 2706 a-d. The supports attached to the side plates ofa battery module according to the present invention, and they causeflexors 2702 to flex when a force is applied to the supports 2702. Thisflexing is illustrated in FIG. 28.

As shown in FIG. 28, when a force is applied to sensor 2700 that causesflexors 2704 a-b to flex, compression and tension forces are applied tothe strain gauges such as strain gauges 2706 a-b, as shown in FIG. 28.

FIG. 29 is a diagram showing how to connect strain gauges of a sensoraccording to embodiments of the present invention in a Wheatstone bridgecircuit 2900. As shown in FIG. 29, circuit 2900 includes a voltagesource 2902 and four strain gauges 2902 a-d. The Wheatstone bridgecircuit 2900 compensates for adverse temperature effects of a sensor, aswill be understood by persons skilled in the relevant art(s). Inembodiments, the strain gauges can be attached to a load cell or flexorsas described herein or directly to pressure plate(s) or to batterycell(s).

FIG. 30 is a diagram showing a circuit 3000 for converting the output ofstrain gauges to a serial digital signal. Circuit 3001 uses acommercially available HX711 chip 3001. Sensors described herein areconnected to connector 3002. The serial output of circuit 3000 isconnected to battery module controller circuit boards 310 a-b usingcircuit connector 3004. In operation, circuit 3000 provides an inputvoltage to the strain gauges of a sensor and monitors the output voltageof the strain gauges in a manner shown, for example, in FIG. 29. Themonitored output voltage is converted to a digital signal by ananalog-to-digital converter, and this digital signal is then seriallycommunicated to another circuit such as a circuit included on batterymodule controller circuit boards 310 a-b, which is further describedbelow.

FIG. 31 illustrates a battery module 3100 having two side plates 3102a-b and eight battery cells 202. The eight battery cells 202 arecompressed by the two side plates 3102 a-b. Pressure applied to sideplates 3102 a-b is transferred to the eight battery cells 202. As shownin FIG. 31, there is room at both ends of battery module 3100 toattached pressure assemblies according to embodiments of the presentinvention.

FIG. 32 illustrates a swelling/pressure sensor 2700 attached to pressureplates 3102 a-b of a battery module 3100 according to an embodiment ofthe present invention. Swelling of a battery cell within the batterymodule causes the pressure plates or side plates 3102 a-b to move, andthis movement is detected by the swelling/pressure sensor 2700.

FIG. 33 illustrates two applied pressure assemblies 3302 a-b attached totwo pressure plates 3102 a-b of a battery module according toembodiments of the present invention. One applied pressure assembly 3302a is attached to the front of the battery module. A second appliedpressure assembly 3302 b is attached to the rear of the battery module.These two applied pressure assemblies 3202 a-b include integratedsensors used to determine/measure the applied force and to detectchanges in the force/movement of the pressure plates 3102 a-b of thebattery module.

FIGS. 34 and 35 are diagrams that depict two embodiments of an appliedpressure assembly with integrated sensor for a battery module accordingto the present invention. FIG. 34 illustrates an applied pressureassembly 3400 with integrated sensor 3402 that has a leaf spring 3404.FIG. 35 illustrates an applied pressure assembly 3500 with integratedsensor 3502 that has a die spring 3504. The applied pressure assembliesare used to apply a predetermined amount of force to the battery cellsthat make up the battery module. The integrated sensors are used todetermine/measure the applied force and to detect changes in theforce/movement of the pressure plates 3406 a-b of the battery module,for example, due to the swelling of a battery cell within the batterymodule.

FIG. 34 illustrates an applied pressure assembly 3400 with integratedsensor 3402 that has a leaf spring 3404. As shown in FIG. 34, theapplied pressure assembly 3400 includes a leaf spring 3404, a bolt 3408,a washer 3410, and a nut 3412. One metal bracket 3416 attaches the leafspring 3404 to a first pressure plate 3406 b. A second metal bracket3414 attaches a second pressure plate 3406 a to the washer 3410/nut3412. Force is applied to the two pressure plates 3404 a-b by turningthe nut 3412 and/or the bolt 3408. The bolt 3408 is in contact with theleaf spring 3404. The force applied is determined by the leaf spring3404 and transferred to the pressure plates 3406 a-b by the two metalbrackets 3414 and 3416. When the desired force is applied, the nut 3412can be tack welded, for example, to the bolt 3408 to ensure that thebolt 3408 does not loosen over time.

In an embodiment, strain gauges 3420 are attached to the leaf spring3404 as illustrated in FIG. 34. In an embodiment, four strain gauges3420 are used. These strain gauges 3420 are connected in a Wheatstonebridge configuration. The strain gauges 3420 are wired to an electroniccircuit that converts the output of the strain gauges 3420 to a digitalsignal as described herein.

FIG. 35 illustrates applied pressure assembly 3500 with integratedsensor 3502 that has a die spring 3504. As shown in FIG. 35, the appliedpressure assembly 3500 includes a die spring 3504, a bolt 3506, a washer3508, and a nut 3510. One metal bracket 3512 attaches the washer 3508 toa first pressure plate 3406 a. A second metal bracket 3514 attaches asecond pressure plate 3406 b to the nut 3510. Force is applied to thetwo pressure plates 3406 a-b, for example, by turning the bolt 3506,which is in contact with the die spring 3504. The applied force isdetermined by the die spring 3504 and transferred to the pressure plates3406 a-b by the two metal brackets 3512 and 3514. When the desired forceis applied, the nut 3510 can be tack welded to the bolt 3506 to ensurethat the bolt 3506 does not loosen over time. The nut 3510 can also betack welded to the second metal bracket 3514 so that it does not rotatewhen turning the bolt 3506.

FIG. 36 illustrates features of an example center plate 3600 and bottomplate 3602 for a battery module according to an embodiment of thepresent invention. As shown in FIG. 36, bottom plate 3602 has one ormore holes 3604 to allow air and/or water to flow through center plate3600 as described herein. In embodiments, center plate 3600 is welded tobottom plate 3602. Battery cells 202 are then attached to center plate3600, for example using a thermally conductive adhesive or tape.

FIG. 37 illustrates a battery module side plate 3700 according to anembodiment of the present invention. Side plate 3700 has heat sinks 3702attached to it, as shown in FIG. 37, to facilitate cooling. Inembodiments, the heat sinks 3702 are attached, for example, by weldingor screws.

FIG. 38 illustrates an example battery module controller 3800 accordingto an embodiment of the present invention. Battery module controller3800 include an AC-to-AC power supply 3802, and isolation transformer3804, and a battery module controller circuit board 3806 that attachesto the top of a battery module as described herein. The battery modulecontroller circuit board 3806 includes a power supply 3808, a CPU 3810,voltage sensors 3812, temperature sensors 3814, a cell balancing circuit3816, and communication circuit(s) 3818. It also includes cell pressuremonitors 3820 that interfaces with the swelling/pressor sensorsdescribed herein that are a feature of battery modules according to thepresent invention.

In operation, AC-AC Power supply 3802 draws power from a power grid andconverts this power to a higher frequency AC power. The higher frequencyAC power output by power supply 3802 is supplied to the power supply3808 on the battery module controller circuit board 3806 and to cellbalancing circuit 3816. Power supply 3808 produces DC power required tooperate the various components of battery module controller circuitboard 3806. CPU 3810 runs the firmware and software that controls theoperation and functions of battery module controller circuit board 3806.These functions include monitoring the voltage, temperature and pressureof the battery cells that make up the battery module controlled bybattery module controller 3800. The functions also include balancing thebattery cells of the battery module and communicating data about thebattery module and battery cells to a higher-level controller such as,for example, a battery rack controller as described below. Cell voltagemonitor(s) 3812, cell temperature monitor(s) 3814, and cell pressuremonitor(s) 3820 are the hardware sensors and circuits needed to monitorthe battery cell voltages, temperatures, and pressures. Cell balancingcircuit 3816 is the hardware needed to provide balancing current/powerto the individual battery cells of the battery module controlled bybattery module controller 3800. More details regarding these functionsand the associated hardware are provided below.

FIG. 39 illustrates more details of an example battery module controller3900 according to an embodiment of the present invention. As describedherein, battery module controller 3900 monitors the voltage,temperature, and pressure of the battery cells by battery modulecontroller 3900. Battery module controller 3900 also balances thebattery cells of the battery module and communicates data about thebattery module and battery cells to a higher-level controller such as,for example, a battery rack controller as described herein.

FIG. 40 illustrates example battery module controllers 4000 according toembodiments of the present invention. In embodiments, battery modulecontrollers provide a constant balancing current to each of the batterycells that are controlled by battery module controller 4000. Inembodiments, the constant balancing current is, for example, 1 amp or 2amps. In one embodiment 4010, the battery module controller provides thebalancing current to each individual battery cell that is selected toreceive balancing current using a star configuration. In anotherembodiment 4020, the balancing current is provided via a loop, whichcharges battery cells selected for balancing and bypasses battery cellsnot selected to receive balancing current as shown in FIG. 40.

FIG. 41 illustrates example battery module controllers 4100 according toembodiments of the present invention. In these embodiments, highfrequency AC current is supplied to the individual battery cells viaisolation transformers 4102 as shown in FIG. 41. The AC current is thenrectified by a rectifier circuit 4104 and used to charge/balance thebattery cells. In an embodiment, the transformer 4106 that is used tosupply the battery cell balancing current can also be used to supply thepower for the other battery module controller components as shown inFIG. 41.

FIG. 42 illustrates an example battery module power supply 4200according to an embodiment of the present invention that can be used togenerate the high frequency AC needed to provide balancing power to thebattery cells.

FIG. 43 illustrates an example cell charging/balancing circuit 4300 thatcan be used in embodiments of the present invention to rectify an ACcurrent and provide the DC current used to balance the battery cells.

FIG. 44 illustrates another example cell charging/balancing circuit 4400that can be used in an embodiment of the present invention to balancethe battery cells.

FIG. 45 illustrates an example cell charging/balancing circuit 4500 thatcan be used in an embodiment of the present invention to charge/balancethe battery cells.

The operation of the above charging/balancing circuits will beunderstood by persons skilled in the relevant art(s) given the circuitdiagrams in the figures and the description herein.

FIG. 46 illustrates an example battery module controller 4610 accordingto an embodiment of the present invention. As shown in FIG. 46, batterymodule controller 4610 includes two battery module controller circuitboards 310 a and 310 b connected together by a ribbon cable 4602. In anembodiment, battery module controller circuit board 310 a includes apower supply 4612 and control and monitoring circuits 4614. Batterymodule controller circuit board 310 b includes monitoring circuits 4616.Battery module controller circuit boards 310 a-b are shown installed ona battery module 4600 according to an embodiment of the presentinvention.

FIG. 47 further illustrate example battery module controller 4610. Asshown in FIG. 47, in addition to power supply 4612, battery modulecontroller 4610 includes a microcontroller unit (MCU) 4620, cell voltagemonitors 4622, cell temperature monitors 4624, cell pressure monitors4626, a cell balancing controller 4630, balancing transformers 4632, andbalancing rectifiers 4634. In an embodiment, MCU 4620 communicates witha higher-level controller using a CANBus communications circuit 4628.The CANBus communications circuit is connected to the higher-levelcontroller using a connector 4640. In an embodiment, the higher-levelcontroller is a battery rack controller as described herein.

In operation, power supply 4612 draws power from a power grid andconverts this power to a higher frequency AC power and DC voltagesneeded to operate the components of battery module controller 4610. Thehigher frequency AC power output by power supply 4612 is supplied to thecell balancing transformers 4632 and balancing rectifiers 4634 forbalancing cells 4636. Power supply 4612 produces DC power required tooperate the various components of battery module controller 4610 suchas, for example, MCU 4620, cell voltage monitors 4622, cell temperaturemonitors 4624, cell pressure monitors 4626, and cell balancingcontroller 4630. MCU 4620 runs the firmware and software that controlsthe operation and functions of battery module controller 4610. Thesefunctions include monitoring the voltage, temperature and pressure ofthe battery cells that make up the battery module controlled by batterymodule controller 4610. The functions also include balancing the batterycells of the battery module and communicating data about the batterymodule and battery cells to a higher-level controller such as, forexample, a battery rack controller as described below. Cell voltagemonitor(s) 4622, cell temperature monitor(s) 4624, and cell pressuremonitor(s) 4626 are the hardware sensors and circuits needed to monitorthe battery cell voltages, temperatures, and pressures. Cell balancingcontroller 4630 is the hardware needed to provide balancingcurrent/power to the individual battery cells 4636 of the battery modulecontrolled by battery module controller 4610. More details regardingthese functions and the associated hardware are provided below.

FIG. 48, which is separated into the partial views shown in FIGS.48A-48Q, is a detailed circuit diagram for battery module controller4610 according to an embodiment of the present invention. As shown inFIG. 48, in an embodiment, two convertors each drive a transformer thatcreate four isolated outputs each. These eight outputs are used with aconstant current circuit to charge one or more of the battery modulebattery cells. Each of the battery cells is monitored for temperature.The circuit is controlled by a microprocessor and communicates to ahigher-level controller using CANBus communications. The microprocessoralso measures the voltage on each cell. The controller also includescircuits that measure the swelling/pressure of the battery cells.

FIG. 49 illustrates an example power supply 4900 that can be used withbattery module controllers according to an embodiment of the presentinvention. As shown in FIG. 49, power supply 4900 includes anelectromagnetic interference (EMI) filter 4902, a rectifier 4904, aquasi-resonance power processor 4906, isolation transformers 4908 and4910, a regulated 5V power circuit, a regulated 12V power circuit, andone or more DC-to-DC 6V power converter circuits used for battery cellbalancing. In embodiments, isolation transformers 4908 and 4910 can bemultiple windings on the same transformer core. Power supply 4900 isconnected to grid power using a connector 4918. In one embodiment,quasi-resonance power processor 4906 is implemented using an InfineonTechnologies 5QR1680AG integrated circuit chip.

FIG. 50, which is separated into the partial views shown in FIGS.50A-50D, is a detailed circuit diagram for power supply 4900 accordingto an embodiment of the present invention. As shown in FIG. 50, powersupply 4900 includes a universal 100V-240V, 50 Hz/60 Hz input withcircuits to limit EMI and inrush current. It also includes an off-linequasi-resonant switch mode power supply. AC power is supplied to aconnector and passes through a fuse and the EMI filter. The inputvoltage is then rectified and stored on a capacitor. The power supplycontroller causes energy to be stored as magnetic flux in thetransformer where it is intermittently removed by two isolated outputdiodes. In an embodiment, the power supply circuit produces +5V and +12Vthat are dielectrically isolated from each other as well as the input.An optocoupler is used to sense and regulate the output voltage.

FIG. 51 further illustrates an embodiment of cell pressure monitor(s)4626 according to an embodiment of the present invention. As shown inFIG. 51, cell pressure monitor 4626 uses a load cell 2312 having aWheatstone bridge circuit 5100 with four strain gauges 5102 a-d. Theoperation of this load cell and Wheatstone bridge circuit is describedabove with reference to FIGS. 23-26.

FIG. 52 illustrates an example battery rack controller 5200 according toan embodiment of the present invention. As shown in FIG. 52, batteryrack controller 5200 includes four DC power connectors 5202 a-d, two ACpower connectors 5204 a-b, two system level communications connectors5206 a-b, two battery module communications connectors 5208 a-b, astatus indicator 5210, and a power switch 5212. Battery rack controller5200 can controller a plurality of battery modules, for example, batterymodules 100, as shown in FIGS. 55 and 57A-C below.

The DC power connectors 5202 a-d are used to connect the battery modulesof the battery rack to a DC bus of a battery energy storage system. Inan embodiment, DC power connectors 5202 a and 5202 c connect batteryrack controller 5200 to the energy storage system DC bus. Powerconnectors 5202 b and 5202 d connect battery rack controller 5200 to thebattery modules that make up the battery rack. AC grid power is providedto battery rack controller 5200 using AC power connector 5204 a. Thispower is then provided to the battery modules using AC power connector5204 b.

System level communications connectors 5206 a-b are used to communicateto a higher-level energy storage system controller. In an embodiment,these communications are conducted using TCP/IP communications. Batterymodule communications connectors 5208 a-b are used to communicate withthe battery modules of the battery rack. In an embodiment, thesecommunications are conducted using CANBus communications. In oneembodiment, CANopen communications are used.

In embodiments of battery rack controller 5200, when powered-on, statusindicator 5210 shows the status of the battery rack, for example, by agreen light indicating everything is operating correctly, or by a yellowor a red light indicating that the battery rack has a minor or a majoroperating issue. Power switch 5212 is used to turn-on and turn-off powerto battery rack controller 5200.

FIG. 53 further illustrates battery rack controller 5200 according to anembodiment of the present invention. As shown in FIG. 53, battery rackcontroller 5200 includes a battery rack controller circuit board 5300, acurrent meter 5302, two voltage meters 5304 a-b, three contactors 5306a-c, a power resistor 5308, and two fuses 5310 a-b. Battery rackcontroller circuit board 5300 includes a microcontroller unit that runsfirmware and/or software that implements the functions of battery rackcontroller 5200. These functions include measuring the battery rackcurrent, battery rack voltage, and communication data with the batterymodule controllers and the battery energy storage system controller. Inoperation, battery rack controller circuit board 5300 opens and closescontactors 5306 to connect the battery modules to the battery system DCbus. Contactor 5306 a and power resistor 5308 are used for pre-chargingand matching the voltage of the battery rack to the DC system bus beforecontactor 5306 b is closed. If during operation an abnormal current orabnormal voltage is detected by current meter 5302 or one of the twovoltage meters 5304 a-b, then battery rack controller circuit board 5300opens the contactors 5306 to isolate the battery rack from the DC systembus until the abnormal condition is corrected. Fuses 5310 a-b areincluded in case of a short circuit or other overcurrent issue. Inembodiments, fuses 5310 are very fast acting fuses.

As shown in FIG. 53, battery rack controller 5200 includes a powersupply to power the components of battery rack controller 5200. Thepower for this power supply is grid power. A relay 5314, controller bybattery rack controller circuit board 5300 controls the supply of thegrid power to the battery modules of the battery rack. In an embodiment,the opening and closing of relay 5314 can be used if needed to reset thebattery module controller of the battery modules that make up thebattery rack.

FIGS. 54A-B illustrate an example battery rack 5400 according to anembodiment of the present invention. As shown in FIG. 54A, battery rack5400 includes a base 5402, doors 5404 a-b, a hood 5406, a watersuppression system 5408, and exhaust ducting 5410. Base 5402 can be usedto move and position battery rack 5400, for example, using a forklifttruck. The doors 5404 a-b allow people to access the battery modules andbattery module controller housed inside the battery rack enclosure. Hood5406 provides space at the top of the battery rack for the firesuppression system sprinkler head(s). Exhaust ducting 5410 is used todraw air through the battery rack and cool the battery modules. It alsois used to direct heat and any gases, for example, in the event that abattery cell vents, outside of the container or room in which thebattery rack is located. In embodiments, the fan(s) for moving airthrough the battery rack are located in the exhaust ducting 5410, whichmakes replacing a fan easy and which is a better design than includingmany small fans inside the enclosure as a part, for example, of thebattery modules.

As shown in FIG. 54B, one or more sprinkler heads 5420 are locatedinside battery rack 5400. In the event of a fire, the sprinkler headsactivate and spray water directly inside battery rack 5400. This wateris collected by the top tray of the battery modules, and the water isthen directed to flow down through the center plates of the batterymodules and over the side plates of the battery module to extinguish thefire and cool surrounding battery modules, so the fire does not spreadto other modules and so the module having the issue does not catch onfire a second time. If a battery were to vent and possibly catch onfire, the heat and gases would be removed from the battery rack viaexhaust ducting 5410.

FIG. 55 illustrates an example battery rack 5500 according to anembodiment of the present invention. As shown in FIG. 55, battery rack5500 includes a base 5502, a door 5404, a hood 5506, a water suppressionsystem 5508, and exhaust ducting 5510. Base 5502 can be used to move andposition battery rack 5500, for example, using a forklift truck. Thedoor 5504 allows people to access the battery modules 100 and batterymodule controller 5200 housed inside the battery rack enclosure. Hood5506 provides space at the top of the battery rack for the firesuppression system sprinkler head(s). Exhaust ducting 5510 is used todraw air through the battery rack and cool the battery modules. It alsois used to direct heat and any gases, for example, in the event that abattery cell vents, outside of the container or room in which thebattery rack is located. In embodiments, the fan(s) for moving airthrough the battery rack are located in the exhaust ducting 5510, whichmakes replacing a fan easy and which is a better design than includingmany small fans inside the enclosure as a part, for example, of thebattery modules 100.

Battery rack 5500, as well as other battery racks described herein,allows water from a commercial fire sprinkler system (for example, seeFIG. 58), provided by one or more sprinkler heads located inside the topof the battery rack, to flow down like a cascading waterfall over thebattery modules 100 to provide cooling and fire suppression. Water flowsdown on the tops of the battery module, where it is collected/gatheredby a plastic top having a berm located on the top of the batterymodules. This water flows down through the middle plate and over theside plates or heat sinks of each of the battery modules or battery cellassemblies and cools the battery cells. As the water exits the middleplate, it is collected/gathered by the battery module below and can thenflow through this battery module's middle plate and over the side platesas described herein.

FIGS. 56A-B illustrate an example battery rack 5600 according to anembodiment of the present invention. As shown in FIG. 56A, battery rack5600 includes a base 5602, a door 5604, a hood 5606, a water suppressionsystem 5608, and exhaust ducting 5610. Base 5602 can be used to move andposition battery rack 5600, for example, using a forklift truck. Thedoor 5604 allows people to access the battery modules 100 housed insidethe battery rack enclosure. Hood 5606 provides space at the top of thebattery rack for the fire suppression system sprinkler head(s). Exhaustducting 5610 is used to draw air through the battery rack and cool thebattery modules. It also is used to direct heat and any gases, forexample, in the event that a battery cell vents, outside of thecontainer or room in which the battery rack is located. In embodiments,the fan(s) for moving air through the battery rack are located in theexhaust ducting 5610.

FIG. 56B is a more detail drawing of battery rack 5600. In FIG. 56B, onecan more clearly see the battery modules 100, and the busbars 5630 a-cand cables 5640 a-b used to connect the battery modules 100 together toform the battery rack.

FIGS. 57A-C illustrate example battery rack products or units accordingto embodiments of the present invention. FIG. 57A shows a battery rack5500 that can be used as a part of a battery energy storage system. Inembodiments, this battery rack includes 15 battery modules 100 accordingto the present invention and forms a nominal 440V battery energy storagesystem. FIG. 57B shows a battery rack product that comprises one batteryrack 5500 and one battery rack 5600 that can be used as a part of abattery energy storage system. In embodiments, this battery rack productincludes 33 battery modules 100 according to the present invention andforms a nominal 1000V battery energy storage system. FIG. 57C shows abattery rack product that comprises one battery rack 5500 and twobattery racks 5600 that can be used as a part of a battery energystorage system. In embodiments, this battery rack product includes 51battery modules 100 according to the present invention and forms anominal 1500V battery energy storage system. In practice, battery energystorage system can be very large and be formed from operating many ofthese battery rack products together in parallel.

FIG. 58 further illustrates an example fire suppression system for abattery rack according to an embodiment of the present invention. Asshown in FIG. 58, a battery rack 5800 has a water fire suppressionsystem with a sprinkler head 5802 that allows water from a commercialfire sprinkler system to flow down like a cascading waterfall over thebattery modules 100 inside the battery rack enclosure to provide coolingand fire suppression. Water flows down on the tops of the batterymodules 100, where it is collected/gathered by a plastic top having aberm located on the top of the battery modules. This water flows downthrough the middle plate and over the side plates or heat sinks of eachof the battery modules or battery cell assemblies and cools the batterycells. As the water exits the middle plate, it is collected/gathered byanother battery module 100 below and can then flow through this batterymodule's middle plate and over the side plates as described herein.

FIGS. 59A-B illustrate a fire suppression system 5900 for a battery rackaccording to an embodiment of the present invention. As shown in FIGS.59A-B, fire suppression system 5900 includes one or more waterdistribution headers 5902 that direct water onto the battery modules5901 housed in a battery rack. The water distribution headers 5902 spaywater directly onto the battery modules 5901 as shown in FIG. 59A. Inthe event of a fire, the water extinguishes the fire and coolsurrounding battery modules, so the fire does not spread to othermodules and so the module having the issue does not catch on fire asecond time.

FIG. 60 illustrates an example battery module 6000 according to anembodiment of the present invention. FIG. 60 is an exploded view ofbattery module 6000 so that the components of battery module 6000 can beseen. As shown in FIG. 60, battery module 6000 includes battery cells202, side plates 203, side bars 204, a bottom plate 302, center plates304, top tray 306, and a cover 6002. Also included in battery module6000 are battery module controller circuit boards 310 a and 310 b,busbars 312, and sensors 314.

In an embodiment, battery module 6000 includes eight battery cells 202.Battery cells 202 are used for storing electrical energy. The eightbattery cells 202 are connected in series using busbars 312. Apredetermined amount of pressure is applied to battery cells 202 usingside plates 203, center plates 304, side bars 204, and springs 206. Sideplates 203 and center plates 304 also provide cooling for battery cells202. Top tray 306 fits on top of battery cells 202 and provides severalfunctions including providing a protective space for sensors 314 andbattery module controller circuit boards 310 a and 310 b. Otherfunctions of top tray 306 are described herein. Cover 6002 fits on topof top tray 306. Battery module controller circuit boards, described inmore detail above, provide battery management functions for batterymodule 6000 such as, for example, monitoring the voltage, temperature,and pressure of battery cells 202.

FIG. 61 illustrates an example battery rack 6100 according to anembodiment of the present invention that houses battery modules 6000. Asshown, the battery modules 6000 include a cover 6002 to facilitate airflow to a cooling air collection system. The battery rack furtherincludes a water distribution system affixed to the back of the batteryrack, depicted between the battery modules and the cooling aircollection system as shown in FIGS. 62A-B.

FIGS. 62A-B further illustrate example battery rack 6100 according to anembodiment of the present invention. As shown in FIGS. 62A-B, batteryrack 6100 includes a fire suppression system 6202 and exhaust ducting6204. Fire suppression system 6202 includes water distribution headersthat direct water onto the battery modules 6000 housed in the batteryrack. The water distribution headers spay water directly onto thebattery modules 6000. In the event of a fire, the water extinguishes thefire and cool surrounding battery modules, so the fire does not spreadto other modules and so the module having the issue does not catch onfire a second time. Exhaust ducting 6204 is used to draw air through thebattery rack and cool the battery modules. It also is used to directheat and any gases, for example, in the event that a battery cell vents,outside of the container or room in which the battery rack is located.In embodiments, the fan(s) for moving air through the battery rack arelocated in the exhaust ducting 6204.

FIGS. 63A-B illustrate an example battery rack 6300 according to anembodiment of the present invention for housing, for example, batterymodules 1800. Battery rack 6300 allows air to enter the bottom of therack and rise to the top of the rack to provide cooling air duringoperation of the batteries. A fan 6302 is located at the top of thebattery rack.

FIG. 64 further illustrates example battery rack 6300 according to anembodiment of the present invention.

FIG. 65 illustrates an example container system 6500 for housing batteryracks according to the present invention that form a battery energystorage system. The container system houses multiple battery racks andprotects the battery racks from the environment. In embodiments,container system 6500 includes an HVAC unit 6502.

FIG. 66 illustrates multiple containers 6602 housing battery racksaccording to the present invention that form a battery energy storagesystem 6600. In addition to the containers 6602, the battery energystorage system 6600 also includes multiple bi-direction power converters6604 for charging and discharging the battery racks housed in containers6602.

FIG. 67 illustrates a building 6700 that houses many battery racksaccording to the present invention that form a battery energy storagesystem.

Those skilled in the relevant art(s) will readily appreciate thatvarious adaptations and modifications of the exemplary embodimentsdescribed above can be achieved without departing from the scope andspirit of the present disclosure. Therefore, it is to be understoodthat, within the scope of the appended claims, the teachings of thedisclosure may be practiced other than as specifically described herein.

What is claimed is:
 1. A battery rack, comprising: a plurality ofbattery modules, wherein each battery module comprising a plurality ofbattery cells, each battery cell being in contact with a side plate; asensor, coupled to the side plate, and configured to detect movement ofthe side plate due to swelling of a battery cell, and a battery modulecontroller configured to receive an output signal from the sensor and togenerate a control signal, in response to the output signal, wherein thecontrol signal is configured to cause the battery module to haltcharging and discharging of the plurality of battery cells of thebattery module; and a battery rack controller having a contactor,wherein the battery rack controller receives the control signal andopens the contactor sufficiently to halt charging and discharging of thebattery module having the battery module controller that generated thecontrol signal.
 2. The battery rack of claim 1, wherein each of thebattery modules further includes: a tray, in contact with the batterymodule, configured to collect water and to direct water to the sideplates of the battery module.
 3. The battery rack of claim 1, whereinthe sensor comprises a flexible section having a circular or oval shape,and wherein a strain gauge is attached to the flexible section.
 4. Thebattery module of claim 3, wherein the flexible section comprises atleast one of metal or plastic.
 5. The battery rack of claim 1, whereinthe battery module controller comprises a power supply configured togenerate an electrical output, and wherein the electrical output fromthe power supply is provided to a balancing circuit configured tobalance electrical input to at least two of the battery cells of thebattery module.
 6. The battery rack of claim 5, wherein the power supplyis coupled to the battery cells of the battery module using at least oneisolation transformer.
 7. The battery rack of claim 1, furthercomprising: a water sprinkler system configured to spray water on thebattery modules.
 8. The battery rack of claim 7, wherein the watersprinkler system is configured to connect to a fire system of abuilding.
 9. The battery rack of claim 7, wherein the water sprinklersystem is configured to connect to a pipe configured to allow water tobe pumped into the battery rack.
 10. The battery rack of claim 1,further comprising: a hood connected to exhaust ducting, wherein theexhaust ducting is configured to remove gases released by a battery cellof the battery rack.
 11. The battery rack of claim 1, wherein thebattery rack comprising: a first housing comprising the battery rackcontroller and a first plurality of battery modules, and a secondhousing, coupled to the first housing, comprising a second plurality ofbattery modules.
 12. The battery rack of claim 11, further comprising: athird housing, coupled to the first housing, comprising a thirdplurality of battery modules.
 13. A battery rack, comprising: aplurality of battery modules, wherein each battery module comprises aplurality of battery cells, each battery cell being in contact with aside plate; a sensor, coupled to the side plate, and configured detectmovement of the side plate due to swelling of a battery cell, a tray, incontact with the battery module, configured to collect water and todirect the water to the side plates of the battery module, and a batterymodule controller configured to receive an output signal from the sensorand to generate a control signal, in response to the output signal,wherein the control signal is configured to cause the battery module tohalt charging and discharging of the battery module; a battery rackcontroller comprising a contactor, wherein the battery rack controllerreceives the control signal and opens the contactor sufficiently to haltcharging and discharging of the battery module having the battery modulecontroller that generated the control signal; and a water sprinklersystem configured to spray water on the battery modules.
 14. The batteryrack of claim 13, wherein the water sprinkler system is configured toconnect to a fire system of a building.
 15. The battery rack of claim13, wherein the water sprinkler system is configured to connect to apipe that is configured to allow water to be pumped into the batteryrack.
 16. The battery rack of claim 13, further comprising: a hoodconnected to exhaust ducting, wherein the exhaust ducting is configuredto remove gases released by a battery cell of the battery rack.
 17. Thebattery rack of claim 13, wherein the sensor comprises a flexiblesection having a circular or oval shape, and wherein a strain gauge isattached to the flexible section.
 18. The battery rack of claim 13,wherein the flexible section comprises at least one of metal or plastic.19. The battery rack of claim 13, wherein the battery module controllerincludes a power supply configured to generate an electrical output, andwherein the electrical output from the power supply is provided to abalancing circuit configured to balance electrical input to at least twoof the battery cells of the battery module.
 20. The battery rack ofclaim 19, wherein the power supply is coupled to the battery cells ofthe battery module using at least one isolation transformer.